3) Which pair of formulas represents the empirical formula and molecular

formula for a certain (the same) compound?

A. CH4 and C2H6

B. CH2O and C4H6O

C. O2 and O3

D. C3H403 and C6H8O

The answer to your question is maybe letter D, but the last oxygen needs a number 6.

Explanation:

The empirical formula gives the actual elements that form part of a molecule but not the total numbers.

The molecular formula gives the total number of atoms of each element in a molecule.

We must factor the molecular formula to know if a formula is the empirical formula of that.

A. CH₄ C₂H₆ = 2 (CH₃) these are not empirical molecular formulas

B. CH₂O C₄H₆O these are not empirical-molecular formulas

C. O₂ O₃ these are not empirical-molecular formulas

D. C₃H₄O₃ C₆H₈O these are not empirical-molecular formulas

the last oxygen needs a number 6 to be

the answer.

D is the correct answer